find d2ydx2 in terms of x and y when y2x3Solutionwe have y2
find d^2y/dx^2 in terms of x and y when y^2=x^3
Solution
we have y2 = x3
differentiating both sides we get:
2y(dy/dx) = 3x2..........equation 1
=> dy/dx =x2/2y ..........equation 2
again deffreentiating both sides of equation 1 we get:
2(dy/dx)(dy/dx) + 2y(d2y/dx2) = 6x
=>2(dy/dx)2 +2y(d2y/dx2) = 6x
putting the value of dy/dx (which we got from equation 1) in above equation we get:
2(x2/2y)2 + 2y(d2y/dx2) = 6x
=> x4/2y2 + 2y(d2y/dx2) = 6x
or 2y(d2y/dx2) = 6x -( x4/2y2)
or
(d2y/dx2) = [6x -( x4/2y2)]/2y
or
(d2y/dx2) = 3(x/y) - (x4/4y3)
